1. Field
The following description relates to a magnetic field sensor testing apparatus and a magnetic field sensor testing method.
2. Description of Related Art
A ‘multi-axis magnetic field sensor’ refers to a sensing device configured to perceive azimuth angle by detecting a magnetic field in an X, Y or Z axis (The ‘multi-axis’ as used herein may include two or three axes).
Typically, it is necessary to directly apply a magnetic field to the X, Y or Z axes which are to be sensed in order to test the multi-axis magnetic field sensor. It is thus necessary to prepare a coil such as an inductor to apply the magnetic field, after which electric current is flowed through the coil for the testing of the magnetic field sensor, while varying the magnetic field according to an intended magnitude.
Korean Patent Publication No. 10-2006-0060666 proposes an apparatus using a two-axis magnetic field sensor to solve problems associated with three-axis compass.
The multi-axis magnetic field sensor can be tested on a wafer or in a package.
To test a magnetic field sensor on a wafer, it is typically necessary to apply a uniform magnetic field to the multi axis directions of the wafer. Accordingly, coils are needed at the X, Y and Z axis directions, respectively. It is especially necessary to employ a larger coil than the wafer to test the Z-axis direction, and also necessary to apply a larger magnetic field because the range of sensing the magnetic field increases. However, such need for applying greater electricity to the coil typically causes problems.
Meanwhile, for testing a sensor in a package, a socket is generally used. Although this testing also requires coils respectively for the X, Y and Z axis directions, smaller coils than for testing on a wafer can be used. However, because it is necessary to place the magnetic field sensor in the package in a socket for testing purposes, separate devices are necessary. Further, because a plurality of magnetic field sensor chips are tested in a sequential order, testing typically takes a longer time and incurs greater costs.